Geographical Peculiarities of Pinus sibirica Du Tour Natural Regeneration as Related to its Seed Crops

Forest ecology faces a significant challenge in understanding the dynamics of populations of forest-forming trees during their renewal phase, as it shapes the subsequent development and structure of forest ecosystems. The forest regeneration process relies on the dynamics of the seed yield of the woody plants and the unique characteristics of their distribution. In the case of the Cembrae sp. five-needled pines belonging, which have wingless seeds, their renewal is closely linked to the activities of Nucifraga sp. birds that scatter the seeds to create food reserves in the soil. This research aims to explore the geographical variations of Siberian stone pine (Pinus sibirica Du Tour) natural regeneration as a function of seed abundance. This study was conducted in three Russian mountain regions known for their forests predominated by Pinus sibirica: the Aldan Highlands, the Northern Urals, and the Khamar-Daban Mountains. It was discovered that each region exhibited distinct patterns in both cone yields and Pinus sibirica regeneration. The fluctuations in the thin-billed nutcracker (Nucifraga caryocatactes macrorhynchos Brehm C. L.) populations during the seed harvest season, influenced by the nature of the seed production dynamics in each region, we believed to play a major role in the quantity of Pinus sibirica seedlings appearing in the subsequent year. These findings explain the observed variations in the renewal dynamics of annual emergent seedlings of Pinus sibirica and its reliance on cone yield in the examined regions.